Re: r336921 broke booting on MBP 2017, EFIRT related

> On 29 Aug 2018, at 15:05, Toomas Soome <tsoome_at_me.com> wrote:
> 
> 
> 
>> On 29 Aug 2018, at 14:53, Yuri Pankov <yuripv_at_yuripv.net <mailto:yuripv_at_yuripv.net>> wrote:
>> 
>> Yuri Pankov wrote:
>>> Konstantin Belousov wrote:
>>>> On Wed, Aug 29, 2018 at 12:37:52PM +0300, Yuri Pankov wrote:
>>>>> Hi,
>>>>> 
>>>>> I've noticed that all recent snapshots (ALPHA3, ALPHA2, ALPHA1,
>>>>> 20180802) fail to boot on MBP 2017:
>>>>> 
>>>>> kbd0 at kbdmux0
>>>>> netmap: loaded module
>>>>> nexus0
>>>>> 
>>>>> Fatal trap 12: page fault while in kernel mode
>>>>> cpuid = 2: apic id = 02
>>>>> fault virtual address  = 0x74c64a50
>>>>> fault code             = supervisor read data, page not present
>>>>> instruction pointer    = 0x20: 0x7abece31
>>>>> stack pointer          = 0x28: 0xffffffff82b2f7c0
>>>>> frame pointer          = 0x28: 0xffffffff82b2f810
>>>>> code segment           = base 0x0, limit 0xfffff, type 0x1b
>>>>>                          = DPL 0, pres 1, long 1, def32 0, gran 1
>>>>> processor eflags       = interrupt enabled, resume, IOPL = 0
>>>>> current process        = 0 (swapper)
>>>>> [ thread pid 0 tid 100000 ]
>>>>> Stopped at      0x7abece31:    calll   *0x18(%rax)
>>>>> db>
>>>>> 
>>>>> Sadly, there's no support for internal keyboard yet (it's connected via
>>>>> SPI), and external USB one stops working.
>>>>> 
>>>>> A (not so quick) bisect is pointing at r336921, which enabled EFIRT.
>>>>> 
>>>>> Some questions here:
>>>>> - is this something that can/should be fixed?
>>>>> - can we print some "enabling EFIRT" message to the console to make
>>>>>     guesses about the problem source a bit easier?
>>>> 
>>>> It is not in 'enabling'.  Looking at the faulting VA, I believe that
>>>> it occurs inside the BIOS code.
>>>> 
>>>> Disable efirt by removing the kernel option, then try to load the module
>>>> at runtime.  Does it still fault ?  Also, get the efi mem map for the
>>>> machine and look at which region the faulting address and the faulting
>>>> instruction belong.
>>> kldload'ing the efirt module gets the same fault.  Several top lines of backtrace:
>>> kernphys() at 0x7abece31
>>> efi_get_time() at efi_get_time+0xd9
>>> efirtc_probe() at efirtc_probe+0x17
>> 
>> For the efi mem map, if I'm understanding it correctly, there's the following:
>> 
>> ...
>>   BootServicesData 00007421d000 000000000000 00000a8b UC WC WT WB
>> ...
>> RuntimeServicesCode 00007ab9f000 000000000000 00000070 UC WC WT WB
>> …
> 
> if my math is correct, this RTS code area will end at 0x000000007abe5000 and if 0x000000007abece31 is fault location, its just after that RTS code area, that is, 7 pages after… meaning you would need to get the next entry:)
> 

ya well, my math does suck because its 0x70 pages, not 70:D

rgds,
toomas